Erinacine

Erinacines are natural substances isolated from the mycelium of Hericium erinaceus (lion's mane mushroom). They belong to the group of cyathin diterpenoids (erinacines A–K, P, Q, S, U) and are subjects of pharmacological research, which largely focuses on the benefits of erinacine on the brain.^{[citation needed]}

Chemical structures of erinacines A–I

Erinacine A

Erinacine A, isolated from the cultured mycelia of Hericium erinaceus, the main representative of this compounds group, has an enhancing effect on nerve growth factor synthesis in vitro.^[1] It also increases the levels of catecholamines in the central nervous system of rats.^{[citation needed]}

Erinacine A has also been prepared by total synthesis.^[2]

Erinacine E

Erinacine E is a kappa opioid receptor agonist.^[3]

Erinacine S

Erinacine S has been shown to cross the blood–brain barrier in vivo, highlighting the bioavailability of this compound in the brain.^{[citation needed]}